FCM analysis for apoptosis after treatment by Annexin V-FITC and PI staining on HepG2 cells. After treatment with different doses of β-elemene for 48 h, apoptosis induction was observed. Apoptotic cells were differentiated from viable or necrotic ones by combined application of annexin V-FITC and PI. This assay was performed in triplicate. A: blank control group; B: 10 μg/mL β-elemene group; C: 20 μg/mL β-elemene group; D: 40 μg/mL β-elemene group. *P<0.05, **P<0.01 versus control group.